Source : WordNet®

blastulae
     See {blastula}

blastula
     n : early stage of an embryo produced by cleavage of an ovum; a
         liquid-filled sphere whose wall is composed of a single
         layer of cells; during this stage (about eight days after
         fertilization) implantation in the wall of the uterus
         occurs [syn: {blastodermic vesicle}]
     [also: {blastulae} (pl)]